Children from Sandy Hook Elementary School in Newtown, Conn., resumed classes for the first time since last month's horrific tragedy. They returned to their old, familiar desks, but in a different building in a different town nearby.

School buses drove down streets lined with green ribbons there Thursday morning, and students were greeted by Sandy Hook Elementary's former principal who retired two years ago.

Inside, the kids found what looked like their old classrooms; their desks, backpacks and even the pencils were all the same.

"When you return to familiarity, in a situation that feels really comfortable, that will really help restore your previous beliefs, restore that world view that might have gotten shaken up by the trauma," said sot Dr. Jamie Howard, a clinical psychologist at the Child Mind Institute.

Students from Wellington Landing Middle School were among those from all over the world who made and sent paper snowflakes to welcome the students back.